Abstract: An apparatus and method are provided for mixing gas and liquid. An impeller is rotatably mounted inside a draft tube having a constricted section. Rotation of the impeller draws liquid down through the constricted portion of the draft tube. A gas delivery system introduces gas under the surface of the liquid downstream from the constricted portion of the draft tube to entrain the gas in the liquid by a venturi effect. The impeller creates a turbulent gas-liquid mixing zone and also projects liquid radially into the gas as it enters the draft tube. The gas-liquid venturi mixer is particularly suitable for treating industrial and municipal waste water, as well as various other liquids. Gases such as air, oxygen, hydrogen, and the like are efficiently dissolved in such liquids during operation of the gas-liquid venturi mixer.

Abstract: An apparatus and method are provided for mixing gas and liquid. An impeller is rotatably mounted inside a draft tube. Inlet baffles are mounted adjacent the inlet end of the draft tube in close proximity to the impeller. In addition, outlet baffles are mounted adjacent the outlet end of the draft tube in close proximity to the impeller. Rotation of the impeller draws liquid down through the draft tube and creates vortices which serve to entrain gas into the liquid. The provision of inlet and outlet baffles directly adjacent the rotating impeller produces high gas entrainment and shear rates and improves gas transfer efficiency. The gas-liquid vortex mixer is particularly suitable for treating industrial and municipal waste water, as well as various other liquids. Gases such as air, oxygen, hydrogen, and the like are efficiently dissolved in such liquids during operation of the gas-liquid vortex mixer.